Source: Fix alpha transparency in Low/Lowest#1477
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With NDIlib_recv_color_format_fastest, the NDI runtime decodes alpha-carrying streams to UYVA (UYVY + separate alpha plane), and ndi_source_thread_process_video2() mapped UYVA to VIDEO_FORMAT_UYVY, silently dropping the alpha plane. Request NDIlib_recv_color_format_UYVY_BGRA for all latency modes: non-alpha sources still decode zero-copy to UYVY, while alpha sources are converted to BGRA by the NDI runtime, preserving transparency. Fixes DistroAV#937
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Fixes #937.
Problem: NDI sources carrying alpha (ProPresenter, FreeShow, vTube Studio, …) lose transparency when the source latency mode is Low or Lowest.
Root cause: with
NDIlib_recv_color_format_fastest, the NDI runtime decodes alpha-carrying streams to UYVA (UYVY + separate alpha plane).ndi_source_thread_process_video2()maps UYVA →VIDEO_FORMAT_UYVY, silently discarding the alpha plane. Verified with a local probe receiver against a BGRA test source:UYVY_BGRA→ BGRA with alpha intact;fastest→ UYVA.Fix: request
NDIlib_recv_color_format_UYVY_BGRAfor all latency modes. Non-alpha sources still decode zero-copy to UYVY (same asfastest); alpha sources are converted to BGRA by the NDI runtime.Notes:
developand was lost in the 6.0.0 rewrite — no shipped release contains it. This PR extends the same approach to Lowest as well.VIDEO_FORMAT_UYVAin libobs (libobs: Add YUVA pixel format obsproject/obs-studio#10345, closed unmerged). This is a minimal alternative that works with stock OBS today.Seeking Testerslabel so CI packages test installers?Testing: built for macOS (6.2.1) and Windows x64 (this branch); verified alpha checkerboard and real ProPresenter/FreeShow feeds render with transparency in Normal, Low, and Lowest. Plugin loads cleanly; no new warnings.